1. A method of selecting a bituminous emulsion with enhanced performance, comprising:
(a) selecting at least one proposed emulsifier comprised of at least about 5% by mass of a cationic nitrogenous compound selected from the group consisting of compounds having a carbonyl carbon atom bonded to a nitrogen atom, compounds having a carbon atom double bonded to a nitrogen atom, and combinations thereof based on the total mass of said proposed emulsifier;
(b) reacting said proposed emulsifier with a carboxylic acid to create at least one proposed carboxylate salt;
(c) mixing bitumen and said proposed carboxylate salt to form at least one proposed bituminous emulsion;
(d) applying said proposed bituminous emulsion to a surface;
(e) measuring coalescence of said proposed bituminous emulsion; and
(f) selecting a bituminous emulsion for paving a surface after said coalescence measuring step and choosing said bituminous emulsion based on said coalescence measurement of said proposed bituminous emulsion.
2. The method of claim 1 wherein said bitumen has a penetration value of about 25 to 450 dmm at 25\xb0 C.
3. The method of claim 1 wherein said proposed bituminous emulsion has a residue of about 35 to 85% based on the weight of the emulsion.
4. The method of claim 1 wherein said bitumen is polymer modified.
5. The method of claim 1 wherein said cationic nitrogenous compound is selected from the group consisting of imidoamines, imines, amidoamines, amides, imadazoles, and combinations thereof.
6. The method of claim 1 wherein coalescence is measured using is a rheology test.
7. The method of claim 1 wherein coalescence is directly measured.
8. The method of claim 7 wherein coalescence is measured using a demulsibility test.
9. The method of claim 7 wherein coalescence is measured using a sand-break index test.
10. The method of claim 1 wherein coalescence is measured within about 48 hours of when said bituminous emulsion is applied to said surface.
11. The method of claim 1 wherein coalescence is measured within about 24 hours of when said bituminous emulsion is applied to said surface.
12. The method of claim 1 wherein coalescence is measured within about 12 hours of when said bituminous emulsion is applied to said surface.
13. The method of claim 1 wherein said proposed emulsifier is comprised of at least about 10% by mass of said cationic nitrogenous compound based on the total mass of said emulsifier.
14. The method of claim 1 wherein said proposed emulsifier is comprised of at least about 20% by mass of said cationic nitrogenous compound based on the total mass of said emulsifier.
15. The method of claim 1, further comprising:
reformulating said proposed bituminous emulsion by repeating steps (a)\u2013(e) if the coalescence of said proposed bituminous emulsion is undesirable, before performing step (f).
16. The method of claim 15 wherein said reformulating step includes increasing the amount of said cationic nitrogenous compound in said proposed emulsifier.
17. The method of claim 15 wherein said reformulating step includes selecting a different carboxylic acid.
18. The method of claim 6 wherein said rheology test is selected from the group consisting of an abrasion test, a tangential sheer test, an impact test, a tensile test, a torque test, a compression test, an adhesion test and a binder viscosity test.
19. The method of claim 18 wherein said rheology test is a sweep test.
20. The method of claim 18 wherein said rheology test is a vialit test.
21. The method of claim 18 wherein said rheology test is a tensile test.
22. The method of claim 1 wherein said carboxylic acid is selected from the group consisting of mono, di- and tricarboxylic acids and combinations thereof.
23. The method of claim 1 wherein said carboxylic acid is selected from the group consisting of acetic acid, formic acid, propionic acid and combinations thereof.
24. The method of claim 1 wherein said carboxylic acid is acetic acid.
25. The method of claim 19 wherein said selected bituminous emulsion has a mass loss from said sweep test that is reduced by at least about 10% at 1 hour compared with a bituminous emulsion hydrochloride salt control.
26. The method of claim 19 wherein said selected bituminous emulsion has a mass loss from said sweep test that is reduced by at least about 20% at 1 hour compared with a bituminous emulsion hydrochloride salt control.
27. The method of claim 19 wherein said selected bituminous emulsion has a mass loss from said sweep test that is reduced by at least about 30% at 1 hour compared with a bituminous emulsion hydrochloride salt control.
28. A method of selecting a bituminous emulsion with enhanced performance, comprising:
(a) selecting at least one proposed emulsifier comprised of at least about 5% by mass of a cationic nitrogenous compound selected from the group consisting of compounds having a carbonyl carbon atom bonded to a nitrogen atom, compounds having a carbon atom double bonded to a nitrogen atom, and combinations thereof based on the total mass of said proposed emulsifier;
(b) reacting said proposed emulsifier with a carboxylic acid selected from the group consisting of acetic acid, formic acid, propionic acid and combinations thereof to create at least one proposed carboxylate salt;
(c) mixing bitumen and said proposed carboxylate salt to form at least one proposed bituminous emulsion;
(d) applying said proposed bituminous emulsion to a surface;
(e) measuring coalescence of said proposed bituminous emulsion using a rheology test within about 48 hours of when said proposed bituminous emulsion is applied to said surface; and
(f) selecting a bituminous emulsion for paving a surface after said coalescence measuring step and choosing said bituminous emulsion based on said coalescence measurement of said proposed bituminous emulsion.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A switching power supply, comprising:
switching circuit for receiving an external power supply and being turned ONOFF so as to output a pulse;
output circuit for receiving an output from the switching circuit to output a voltage to an outside and producing a driving voltage;
start-up circuit including a transistor for receiving the external power supply to produce a driving voltage;
control circuit driven by the driving voltage produced by the output circuit or the driving voltage produced by the start-up circuit for turning ONOFF the switching circuit; and
voltage switching circuit for switching a voltage to be provided to a control electrode of the transistor to a voltage that is less than a minimum input voltage required to drive the control circuit, when the driving voltage produced by the output circuit is greater than the minimum input voltage required to drive the control circuit, wherein:
when the driving voltage produced by the start-up circuit is greater than the driving voltage produced by the output circuit, the driving voltage from the start-up circuit is provided to the control circuit; and
when the driving voltage produced by the start-up circuit is less than the driving voltage produced by the output circuit, a current path is blocked in the start-up circuit so that no driving voltage is provided from the start-up circuit to the control circuit,
wherein the voltage switching circuit comprises a switching element for being turned ONOFF based on the driving voltage produced by the output circuit so as to switch the voltage to be provided to the control electrode of the transistor,
the start-up circuit further comprises a constant voltage generation section for receiving the external power supply to provide a constant voltage to the control electrode of the transistor,
the transistor is a MOSFET, the constant voltage generation section comprises a Zener diode whose cathode is connected to a gate of the MOSFET, and the start-up circuit further comprises a first resistor provided between a drain of the MOSFET and an external power supply line, and a second resistor provided between the gate of the MOSFET and the external power supply line, and
the voltage switching circuit comprises a transistor and a third resistor, one end of the third resistor is connected between the second resistor and the Zener diode, and the other end of the third resistor is connected to the transistor comprised within the voltage switching circuit.
2. A switching power supply according to claim 1 wherein:
when the driving voltage produced by the start-up circuit is less than the driving voltage produced by the output circuit, the transistor is turned OFF based on an electric potential difference between the voltage to be provided to a control electrode of the transistor and the driving voltage produced by the output circuit, so that no driving voltage is provided from the start-up circuit to the control circuit.
3. A switching power supply according to claim 1, wherein the start-up circuit further comprises a thermal protection element whose resistance increases when a temperature thereof exceeds a predetermined temperature.
4. A switching power supply according to claim 1, wherein the start-up circuit further comprises a fuse element that is opened when a current flow therethrough exceeds a predetermined value.